Increased inflammatory potential of diet is associated with bone mineral density among postmenopausal women in Iran.

Purpose: Diet has been shown to be associated with bone mineral density (BMD); however, the inflammatory potential of diet in modulating BMD has not yet been studied.

Methods: We examined the association between a newly developed dietary inflammatory index (DII) and BMD in a sample of postmenopausal Iranian women. In this cross-sectional study, 160 postmenopausal women aged 50-85 years were studied and their femoral neck and lumbar spine BMDs were measured by dual-energy X-ray absorptiometry. The DII was computed based on dietary intake assessed using a previously validated, 168-item semiquantitative food frequency questionnaire. Logistic and linear regression models were fit to derive beta estimates and odds ratios (ORs), with DII fit as continuous and as a dichotomous variable.

Results: After adjusting for potential confounders, women with higher DII scores were more likely to have BMD below the median in the lumbar spine with the DII being used as both a continuous variable [ORcontinuous 1.64, 95 % confidence interval (CI) 1.11-2.43, p value = 0.01; one-unit increase corresponding to ≈17 % of its range in the current study] and a categorical variable (ORDII>-0.06/≤ 2.30, 95 % CI 1.05-5.07, p value = 0.04). Similar associations were observed when lumbar spine BMD was used as a continuous outcome. No significant association was observed with BMD in femoral neck, although the direction was along expected lines.

Conclusion: These data suggest a pro-inflammatory diet, as indicated by increasing DII score, may be a risk factor for lower BMD in lumbar spine in postmenopausal Iranian women.